philippis,s, it's s interesting visitingng the phililippines so often, because going back to the philippines anandng around you see small children in the streets with no clothes and they are dirty and they are bathing in the rain, in the sewers. but they still smile. they still are having a good time. and then i it just makakes me t about t how when i g go home fr schohool and i have a hot showe it's -- i i take it for grarant. as we start helping and contributing i in small ways eventually it turnrns out to be bigger. and when more people get involved, i think thatat's when we can really help other people. ♪ >> and now to our global ideas series. this is where we report about people determined to preserve our planet's biodiversisity. this time we're in nepal in a mountainous region battling the efeffects of erorosion. when m mud slides ococcur here frequently bury houses beneath them. what can be done about it? local residents are setting their hopes on a very simple plant -- a kind of grass. our reporter wolf geb hardt went to the region around pokhara to find out more. >> once again, the rain i